There are various known constructional forms of wide-angle hinges. Such a known hinge assembly comprises a hinge section on the frame and a door leaf hinge section secured to the wing or door leaf. The hinge sections are connected to one another by double-armed link members pivotable about a common pivot. One of the link members is hingedly connected to the door leaf hinge section by an intermediate link. Such a linkage arrangement includes a spring mechanism which provides a closing pressure to the assembly and locks the door leaf in a closed position.
With one constructional form of such a door hinge assembly, a spring loaded pressure member is arranged in the region of the common pivot axis. The pressure member is arranged on one of the double-armed link members and bears on the free end of the other link member which is formed as a control cam. A helical spring is used as the spring element in this known hinge assembly.
With another known constructional form of wide-angle hinge, a spring lever is mounted on the common axis or pivot of the double-armed link members. The spring lever cooperates with a latching action at its free end portion with the pivot of the intermediate link in the closed position of the hinge. In this instance, the spring mechanism is located on the linkage of the double-armed link members which are pivotable in scissor-like fashion with one another about a common pivot point. It is necessary to have a high precision with respect to the various components used in the hinge assembly to ensure the engagement of the members in association with the spring mechanism. Furthermore, it is extremely difficult to convert the normal hinge into a spring hinge and vice versa. Thus, neither of these known constructional forms of wide-angle hinge assembly is satisfactory.